PHYS 101 Lecture Notes - Fundamental Frequency

• School: McGill University
• Department: Physics
• Course: PHYS 101
• Professor: Kenneth Ragan

Document Summary

Example: the voice of a person who has inhaled helium sounds very high pitched. Velocity increases by three and the frequency increases because the wavelength remains unchanged. Example: at 20 degrees c, (take v = 343 m/s), how long an organ pipe do you need for fundamental to be 294 hz: 294 = (2)(343/l, l = 0. 58 m. Example: an organ pipe resonates at 264 hz. 440 hz, and 616 hz but not at any frequencies in between. Is it an open or a closed pipe: closed pipe. This is because there is a gap of 176, and then if you subtract 176 from 276, you get 88, which is not the other. Sound waves come together to form interference. Spatial interference (same region) can happen constructively or destructively. Usually only specific wavelengths can interfere destructively. Interference can also happen in time such as in beats where there are two waves of similar frequency but not the same frequency.